Line Photo of gross gutWhat causes the signs of Johnes disease?
M. paratuberculosis infects the last part of the small intestine (called the ileum) and causes a certain kind of inflammation called granulomatous inflammation. This inflammation thickens the intestinal wall, preventing it from functioning normally. This, among other factors, causes diarrhea and poor absorption of nutrients. As a result, even though animals will seem to be feeling and eating well, they will rapidly lose weight.
